The distinct, often chemical-like odor accompanying a newly unwrapped mattress, known as “new mattress smell,” results from the manufacturing process. This smell is the physical manifestation of off-gassing, where volatile organic compounds (VOCs) are released into the air. Parents are concerned about the risk these emissions pose to an infant’s sensitive, developing system. Understanding the source of the smell and how to mitigate it is necessary for preparing a safe sleep environment.
What Causes the New Mattress Odor
The “new mattress smell” is caused by the release of Volatile Organic Compounds (VOCs), which are carbon-containing chemicals that easily convert from a liquid or solid state into a gas at room temperature. This off-gassing occurs as the compounds used in production stabilize and evaporate into the air. The process is especially noticeable in mattresses compressed and sealed in airtight plastic for shipping.
Polyurethane foam, a primary component in memory foam and many conventional mattresses, is a major source of VOCs. Adhesives and glues used to bond layers together often contain compounds like formaldehyde and benzene, which contribute to the odor. Flame retardant chemicals, which are added to meet mandatory fire safety standards, can also be a source of these gaseous emissions.
The smell is strongest immediately after the mattress is unboxed, but low-level emissions can continue for days, weeks, or even months. Studies indicate that the release rate of these compounds can be accelerated by body heat and pressure, meaning the mattress off-gasses more while it is being used. Although the odor itself fades, the continued release of odorless VOCs means the issue is not resolved once the smell is gone.
Potential Health Effects on Infants
Infants are uniquely vulnerable to the effects of off-gassing due to physiological factors that increase their exposure relative to adults. Babies have a faster respiration rate, meaning they inhale a greater volume of air per pound of body weight. Their internal organs and nervous systems are still developing, making them less efficient at processing and eliminating chemical pollutants.
The close proximity of an infant’s face to the mattress surface significantly increases the localized concentration of VOCs in their breathing zone. Research using infant manikins showed that VOC concentrations in the breathing zone could be nearly twice as high as the bulk room air. Furthermore, the VOC concentrations inside the mattress foam itself can be many times greater than the surrounding air.
Short-term exposure to these airborne chemicals may cause immediate symptoms such as eye, nose, and throat irritation. Infants with respiratory sensitivities, such as asthma, might experience an exacerbation of their symptoms. Long-term exposure to certain VOCs, like formaldehyde and some flame retardants, is linked to serious concerns. These concerns include potential interference with brain development, hormone function, and an increased risk of respiratory problems later in childhood.
Practical Steps to Minimize Exposure
Parents can actively reduce their infant’s exposure by implementing a systematic off-gassing process immediately after purchase. The first step is to remove the mattress from all plastic packaging immediately, even if the nursery is not yet ready. This allows the VOCs trapped during shipping to begin dissipating.
The new mattress should be placed in a well-ventilated space away from the nursery, such as a garage or a spare room, for an extended period. Opening windows and using a fan to direct air outward maximizes air exchange and speeds up the release of VOCs. Exposing the mattress to direct sunlight and warmth can accelerate the rate at which the compounds evaporate.
Although many manufacturers suggest off-gassing for 24 to 72 hours, parents should consider airing the mattress out for a few weeks, as low levels of VOCs can persist after the odor is gone. Timing the mattress purchase well ahead of the baby’s arrival allows for this extended ventilation period. Using a crib mattress cover made from materials like organic cotton or food-grade polyethylene can provide a final barrier against lingering emissions.
Decoding Mattress Safety Certifications
Choosing a mattress with recognized safety certifications is the most proactive way to minimize VOC exposure before the product enters the home. These third-party standards certify that the materials and the final product meet strict limits for chemical emissions, assuring parents the mattress was manufactured with chemical safety in mind.
The CertiPUR-US certification specifically applies to the polyurethane foam used in the mattress. CertiPUR-US certified foam is guaranteed to be made without ozone depleters, heavy metals, formaldehyde, and certain flame retardants, and must meet a low-emission standard for VOCs.
The GREENGUARD Gold certification is a more stringent standard that measures the actual chemical emissions of the finished product as a whole. Products must undergo testing in environmental chambers and meet stricter limits for over 360 VOCs and total chemical emissions. This standard specifically accounts for the safety of sensitive populations like children.
Other certifications, such as the Global Organic Latex Standard (GOLS) and Global Organic Textile Standard (GOTS), ensure that natural materials like organic latex and cotton meet rigorous ecological and chemical safety criteria.